Keypad Switching & Scanning - LG GW520 Service Manual

3. BB Circuit Technical brief
3.9 Keypad switching & scanning
The keypad interface is a peripheral which can be used for scanning keypads up to 8 rows and 8
columns . U400(key encoder) supports the key canning process.
KEY_COL7
KEY_COL6
KEY_COL5
KEY_INT
KEY_I2C_SCL
( High state )
LGE Internal Use Only
2V62_VIO
1
TEST
2
SEL_28P
R410 470 3
P57
4
R414 470
P56
R418 470 5
P55
6
P17
7
P15
VA401
EVLC5S0250
VA402
EVLC5S0250
C417 27p
C418 27p
C419 27p
M W E
KEY_ROW0
Q A R
KEY_ROW1
DOT S D
KEY_ROW2
RIGHT FN F
KEY_ROW3
Z(7) X(8)
SHIFT Z X
KEY_ROW4
Vol_Up Vol_Down
KEY_ROW5
KEY_COL0
KEY_COL1
KEY_COL2
KEY_COL3
KEY_COL4
KEY_COL5
KEY_COL6
KEY_COL7
( Low state )
[Figure 3.9-1] Qwerty key circuit diagram
GW520 service manual
2V62_VIO
KEY_I2C_SDA
21
P40
20
P41
19
P42
U400
18
P43
17
P44
EUSY0300004
16
PP2106M2
P45
15
P46
VA400
EVLC5S0250
T I U
Y H J
G SPACE K
C V B
? (#, )
QUES MESSAGE LEFT DOWN
Cam
Touch
Shutter
Lock Send
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R404 470
KEY_ROW0
R407 470
KEY_ROW1
R411 470
KEY_ROW2
R415 470
KEY_ROW3
R419 470
KEY_ROW4
R422 470
KEY_ROW5
R425 DNI
O UP
P BACK
L COMMA
N ENTER
Sym
Sym
End
Multi
Only for training and service purposes